// Cross-browser implementation of element.addEventListener()
function addListener(element, type, expression, bubbling)
{
    bubbling = bubbling || false;

    // Standard
    if( window.addEventListener )
    {
        element.addEventListener(type, expression, bubbling);
        return true;
    } else if( window.attachEvent )

    // IE
    {
        element.attachEvent('on' + type, expression);
        return true;
    }

    // Error
    else
    {
        return false;
    }
}
